The age of Weichselian main ice marginal positions in north-eastern Germany inferred from Optically Stimulated Luminescence (OSL) dating
During the past 130 years, classification of the Weichselian Pleniglacial in north-eastern Germany was mainly based on morphostratigraphical interpretations. In general, three main ice marginal positions are distinguished. The ice advance to the southernmost, relatively weakly developed ice marginal...
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| Other Authors: | , , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
2011
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| Subjects: | |
| Online Access: | https://refubium.fu-berlin.de/handle/fub188/4354 https://doi.org/10.17169/refubium-8554 https://nbn-resolving.org/urn:nbn:de:kobv:188-fudissthesis000000022882-1 |
| Summary: | During the past 130 years, classification of the Weichselian Pleniglacial in north-eastern Germany was mainly based on morphostratigraphical interpretations. In general, three main ice marginal positions are distinguished. The ice advance to the southernmost, relatively weakly developed ice marginal position of the Brandenburg phase has traditionally been ascribed to the Last Glacial Maximum (LGM) of the Scandinavian Ice Sheet (SIS). The Frankfurt phase is usually interpreted as a halt during the downmelting of the glacier. The most prominent ice marginal position in north- eastern Germany is that of the Pomeranian phase. Owing to the absence of recent geochronological data of the Weichselian ice advances, the commonly used ages of ice marginal positions are only estimates or are based on extrapolations from 14C ages of underlying organic sediments. However, during the past few years a number of studies have been conducted to set up a chronology based on geochronometrical data. In this study fluvioglacial sediments from outwash plains associated with the Brandenburg phase and the Pomeranian phase were dated by means of Optically Stimulated Luminescence (OSL) of single aliquots and single grains of quartz. Recently, additional ages from Surface Exposure Dating (SED) of erratic boulders using cosmogenic 10Be have been published. To compare the results from these different approaches, the type and position of the sampled material within the glacial landscape system have to be considered. Consequently, different geomorphological processes are datable using either OSL or SED techniques. Therefore a process-based interpretation for numerical ages from OSL and SED in glacigenic landscapes is introduced. From the results of the OSL analyses from the Brandenburg and Pomeranian phases as well as a thorough reassessment of the available 10Be exposure ages, a synthesis was achieved in terms of ice dynamics and ice retreat patterns during Marine Isotope Stage (MIS) 2. One of the main findings is the evidence for a twofold ... |
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